Madonna reignited her Lady Gaga spat on Saturday by accusing the Poker Face star of imitation.

The pair became embroiled in a pop feud last year over Gaga's anthem Born This Way, which was widely compared to Madonna's 1989 single Express Yourself.

Madonna previously joked about taking credit for helping to write the track, and has even performed a sly mash-up of both songs during her MDNA tour.

The Material Girl took another swipe at her rival at her concert in Atlantic City, New Jersey as she dedicated her song Masterpiece to Gaga, telling fans, "I'm gonna dedicate this next song to Lady Gaga. 'Cause you wanna know something? I love her. I love her. I do love her. Imitation is the highest form of flattery..."

She then teased, "One day, very soon, we're gonna be on stage together. Just you wait."